Cold galvanized / Hot-dipped = Difference?

[captain]

Here it is again. The absolutely best do it yourself tank coating.

http://www.zrcworldwide.com/p_galvilite.asp

 

[Hoosier]

Yes, ZRC spray is more than enough for an individual operator.....

 

[XS Scuba]

Hey SB:
I attached a few images from my last trip. It's quite an impressive process.

Mike, that's a fantastic picture. Got any more? I'd love to see how they're made!!

 

[Land Locked]

Hey SB:
I attached a few images from my last trip. It's quite an impressive process.

Mike,

If it so impressive; why are my LP77's showing a rust out break after one year of fresh water diving? Please contact me on this, my phone number is on your voice mail. I need to know what we are going to do about these tanks.

Thanks.

 

[crpntr133]

Just so others know. I had the same issue as Land Locked. Mike shipped me two new ones and I returned the others. They even paid for return shipping.
There has been at least one batch that had a bad finish on them and XS is aware of this.

However I have to wonder myself how "impressive" this finish is. I hope that my new ones don't rust like the last ones. If they do I will go with another set of LP85's, which I love.

 

[rcontrera]

Geeze guys ... he said the HOT DIPPED facility was quite impressive ... not the spray booth!

 

[pescador775]

Is this "cold galvanized" finish a paint? Are we being coy about this or did I miss something? What happened to metallizing, the use of a hot, plasma jet to deposit zinc? I have some surplus tanks that were flame sprayed thirty years ago and they are holding up with one having some minor rust bleed. The metallized finish is porous and holds paint tightly. So, a touch up with galvalite works well. Problem solved.

PS, the hot dip process is impressive. It takes a lot of force to ram those cylinders into molten metal, buoyancy and all.

 

[SparticleBrane]

Anyone know why Worthington cylinders have the traditional 'spangle' look of hot-dip galvanizing, while PST cylinders don't? (they are very shiny but I've never seen the 'spangle')

 

[Leadking]

To the best of my knowledge PST added aluminium to their zinc to make it "shinier". We made an inquiry to Worthington's applicator and the response came back that they would not contaminate their one million pound zinc bath to make it look "prettier". If you look at properly coated galvanized surfaces around you, lightpoles,sheet metal, etc., you will see the "spangle"

 

[pescador775]

PST may have been using Galfan, a 5% Al Zn alloy. It is a tough, long lasting hot dip coating, probably more corrosion resistant than a pure Zn galvo.

I repeat: what is a cold galvanizing as mentioned in regards to the LP 77 tank?